Stanley Kubrick’s 1964 comedy Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb, shot by Gilbert Taylor, BSC, has long been considered a gem in the Columbia Pictures library, and Sony Pictures recently gave it added luster with a 4K digital restoration, the first such treatment for a black-and-white title. “We felt that the only way to do the film justice, given the many different [film] elements, their poor condition, and the need to maintain the filmmakers’ aesthetic intentions, was to use a complete 4K digital workflow,” says Grover Crisp, vice president of asset management and film restoration at Sony Pictures. “It’s no secret that the original negative has not existed for 40 years. For many years, Mr. Kubrick had control of the title, and when we needed a print, he would oversee the making of it. Certainly the film is worthy of the highest-quality preservation and restoration. It never had the careful treatment it deserved.”

Crisp began examining restoration options for Dr. Strangelove in 2003, as the picture’s 40th anniversary approached. There were chemical stains, scratches and dirt either printed into or physically on all existing film elements, “just about any problem you can think of,” says Crisp. “Some material wasn’t manufactured that well when the film was new, and some had not been handled well for many years. We determined the best elements for restoration were a fine-grain master positive, a duplicate negative and a print; each element was a different number of generations away from the original negative, resulting in wide variations in density and contrast.

“In 2003, digital film restoration at 4K resolution from beginning to end wasn’t really being done,” he continues. “Then, about a year ago, I began discussing this film with the people at Cineric, a New York lab we had used for other restoration projects. They were looking into creating 4K workflows, including digital intermediates [DIs]. For several years, I’ve felt that the DI process is a good model for digital film restoration, but even today, 4K is not routine. Cineric was having specific equipment built for that purpose. Eventually, we decided to go into the project.”

Cineric’s proven expertise with photochemical film restoration gave Crisp additional confidence. “It helps a great deal to have people doing the digital work who have experience with traditional photochemical processes — people who know film, how it works and how to handle it, and what you can and can’t get out of it,” he says. “I’ve found that it’s very easy for people who are not steeped in film history from a technical perspective to make some drastic mistakes, even if they have the best intentions.”

Cineric spent about six months on Dr. Strangelove. Its team began by sorting through the supplied film elements and choosing the best-quality sequences or, in some cases, individual frames. “In some cases, we had to take a shot from a print,” recalls Dan DeVincent, Cineric’s digital director and restoration specialist. They used a specially adapted Oxberry film scanner to convert the various elements into data files in 10-bit log DPX, and DeVincent created look-up tables (LUTs) designed to optimize the scanner for each element and achieve the dynamic range of 35mm film. “We could use an LUT on the scanner to bring a shot from the print a lot closer to the fine-grain, and bridge it further using density and contrast correction,” says DeVincent. “After noise and dirt removal, we used a digital filtration process to make the final blend.”

Cineric engineers developed a wetgate scanning technique that eliminated many flaws. Da Vinci’s Revival automated image-restoration software found and fixed other imperfections. During later passes, the Cineric team corrected more dirt and scratches, as well as anomalies such as flicker and unsteadiness. Density fluctuations were addressed in a final color-correction pass. “We’re working at a very high level of technology, but the last 10 yards is the human factor,” notes DeVincent. “Even the automated tools need the correct calibration, or the result is either artifacts introduced or anomalies left in the image. There’s a tremendous amount of sensitivity required to maintain the original feel of the film. We had several prints that were approved by Kubrick’s team, and Leon Vitali, who worked closely with Kubrick for many years, was a big help to Grover and me in the early stages in terms of the correct look for the film. But we also had to use our knowledge of the characteristics of films and processes of that period.”

One flaw that required special attention showed up in the main title sequence. “They were artifacts that were probably left over from the high-contrast elements originally used to make the main titles,” says DeVincent. “They were probably always there. Back then, most opticals were not made at the quality they are today. It’s the kind of thing that automated restoration tools have a hard time with because the flaws are not consistent, and they are very low in density, sometimes transparent to a degree. Automated tools tend to leave artifacts in that situation. Grover felt any artifacts were unacceptable, and after frame-by-frame digital cleaning, it looked great.”

Sometimes judgment calls had to be made on “mistakes” that were part of the original experience of seeing the film. The Cineric team deferred to Crisp on these questions. “There are a couple of model shots where you can see the wires, and Grover felt that was part of the film’s historical value — it represents the way things were done at the time,” says DeVincent.

The series of atomic explosions that end Dr. Strangelove necessitated another judgment call. Most of the shots appear to have originated as 16mm stock shots, and they exhibited a lot of dirt and scratches; this was compounded by additional stains printed into the surviving 35mm elements. The decision was made to clean these shots up.

A Lasergraphics Producer 2 Motion Picture Film Recording System was used to record out to film. Because the recorder had been designed for use with color intermediate film, the film-out process had to be adapted for Dr. Strangelove. Cineric used other proprietary LUTs to ensure that any future home-video editions of the picture retain the exact look of the restored film master.

Because the Dr. Strangelove restoration broke new ground, Cineric and software companies Autodesk and da Vinci worked hand in hand to refine the tools as the project proceeded. “We could give those companies valuable feedback, and they could give us new versions and tools to test,” says Balazs Nyari, president of Cineric. “That kind of collaboration was extremely helpful. Digital restoration is still a young science, and the technology is evolving very quickly. Collaboration is good for both companies; we get the customized tools we need, and they see which refinements would be most beneficial.”

A pristine print of the restored Dr. Strangelove premiered at the London Film Festival last fall. “We had a great response from the audience,” says Crisp. “Festival audiences are especially appreciative of this kind of work.”